In serial data communication, the channel through which information is transmitted imposes a limit on the bandwidth capacity, or rate at which information may pass through the channel. One significant limitation on achievable bandwidth is known as inter-symbol interference, which occurs when a portion of a signal representative of one bit of information interferes with a different portion of the signal representative of a different bit of information. While the portions of the signal corresponding to respective bits are transmitted such that they occur at different times (i.e., within respective bit periods), efforts to exploit more and more of a media's theoretical available bandwidth results in a concomitant increase in the likelihood that a transmitted pulse will be “chirped” or spread, at lower power, over consecutive bit periods before reaching the receiver.
Besides attenuating the maximum energy contained in any one-bit period, the affected pulses interfere with adjacent bits. Since adjacent bits may not be correlated consistently, the interfering bits or pulses have a direct and substantial impact on the effective noise power and thus reduces the signal to noise ratio.
While it is known to employ equalization in the receiver using analog circuitry, such techniques are generally considered to be too complex and or expensive for applications involving transmission at higher bit rates.
The invention is therefore directed to the problem of developing a system and method capable of extending the benefits of equalization to higher bit rate transmission.